tl;dr Want a permanent transaction? Use cash or Zelle. Want the ability to reverse a transaction or dispute a charge? Use a check or credit card.
The following scam works with craigslist + paypal, but not zelle:
You sell me an expensive item. I paypal you the money. You check your account and see that the money landed. I walk away with the item and immediately reverse the paypal transaction.
Note that the “I sell you a stolen/broken thing that will definitely be traced to you” scam works on both paypal and zelle, since the time to discovery of the scam is long enough to pull the money out of PayPal.
I’m not sure how hard it is to set up a burner zelle account and use it for untraceable crimes. It’s apparently easy to do that with paypal.
But, to your point, yes, they’re both pretty terrible services from a consumer protection standpoint.
(I think these are all Zelle scams these days. I don't really know what Zelle is, but it seems like all the banks got together and were like "how can we really screw over our customers?" and this is what they came up with. You really can't reverse transactions? Why would I use a bank for that when I can easily lose all my money to scams with Bitcoin? It's so crazy to me.)